Biodiversity is the variation in living organisms, viewed within a given habitat, ecosystem or in the world as a whole. The concept is usually applied to the species diversity, although the notion of genetic biodiversity is applied to the variation in genes within an individual species. While most people think of rainforests as loci of great biodiversity, biomes such as oceans and grasslands are the likely repositories for even greater variation. Retention of diverse biota is important, since intact ecosystems are thought to be essential for provision of ecosystem services to humans, including maintenance of a diverse foodbank, pollination, clean water, flood control, pest control, waste decomposition, biomass energy resources and climate stability. Biodiversity is presently critical since we live in the era of the Mass Holocene Extinction, a period of species loss caused by man, and unrivaled in rate of species loss. Although the number of total species numbers in the tens of millions, most have not yet even been described. The extinction of a species is almost always related to destruction of habitat or man-made pollution.
The Spinner dolphin (Stenella longirostris), a marine mammal in the family of oceanic dolphins, engages in formation of small schools. This cetacean species evinces a dominance...
California coastal sage and chaparralLast Updated on 2014-03-06 18:01:11
The California coastal sage and chaparral ecoregion, located along the southern and central coast of California, has extremely high levels of species diversity and endemism. The coastal sage scrub is an endangered ecosystem that contains a number of endangered species. The California Gnatcatcher is currently being used as an umbrella species to protect the endemic flora and fauna of this region from urban development. The region is listed as an Endemic Bird Area with a large number of endemic scrub species. Generally located on high value coastal zone real estate and threatened by land development, the ecoregion represents the struggle between ecological preservation and human development.
The California coastal sage and chaparral encompasses coastal terraces, plains, and foothills along the Pacific coast of northwestern Mexico and southern California, USA. The Santa Rosa Mountains... More »
Palouse grasslandsLast Updated on 2014-03-06 15:18:43The Palouse grasslands ecoregion extends over eastern Washington, northwestern Idaho and northeastern Oregon. Grasslands and savannas once covered extensive areas of the inter-mountain west, from southwest Canada into western Montana in the USA. Today, areas like the great Palouse prairie of eastern are virtually eliminated as natural areas due to conversion to rangeland. The Palouse, formerly a vast expanse of native wheatgrasses (Agropyron spp), Idaho Fescue (Festuca idahoensis), and other grasses, has been plowed and converted to wheat fields or is covered by Drooping Brome (Bromus tectorum) and other alien plant species.
The Palouse lies in the rain shadow of the Cascades and has a generally semiarid climate. This climate is similar to that of the annual grasslands of California, yet the Palouse historically resembled the mixed-grass vegetation of the Central grasslands,... More »
Beringia upland tundraLast Updated on 2014-03-06 15:01:09
The Beringia Upland Tundra consists of three disjunct areas on the Bering Sea coast of Alaska, one comprised of the upland and mountainous areas of Seward Peninsula, one corresponding to the hills and mountains of the Ahklun and Kilbuck mountain ranges in southwest Alaska, and one of much smaller extent on the western half of St. Lawrence Island in the northern Bering Sea. These areas are similar in their varied terrain and elevation, and corresponding variety of vegetation, habitats, and communities. The ecoregion consists of steep, jagged mountain ranges set among large areas of rolling hills, broad valleys, and lowlands. Elevation ranges from sea level to 500 meters (m) in the hilly uplands to over 1,500 m in the tallest ranges. Plant communities respond to these differences in topography and accompanying drainage. Low-lying, poorly drained areas support wet graminoid... More »
Beringia lowland tundraLast Updated on 2014-03-06 14:57:34
The Beringia lowland tundra ecoregion is formed by three major disjunct areas along the Bering Sea coast of Alaska from the base of the Alaska Peninsula to Kotzebue Sound, as well as one smaller area on the east side of St. Lawrence Island and St. Matthew Island. The ecoregion is characterized by low, flat, or gently rolling terrain, wet soils, and resulting predominance of wet and mesic graminoid herbaceous vegetation. In better drained areas, especially in the somewhat more rolling portions of the section surrounding Bristol Bay, dwarf shrub communities occur interspersed with the wet herbaceous tundra, dominated by sedges, including Eriophorum angustoifolium and Carex spp. Dwarf shrub vegetation is usually dominated by ericaceous species, including crowberry (Empetrum nigrum). In some limited areas of favorable soil drainage and microclimate, stands of black and white spruce... More »
Edwards Plateau savannaLast Updated on 2014-03-05 14:08:03
The Edwards Plateau Savannas form an important part of the Texas Hill country, a moderately-sized ecoregion separated from adjacent units by a distinct soil type (mollisols) and a vegetation type distinguished by juniper-oak savanna and mesquite Acacia savanna underlain by mid to short grasslands. In other aspects, the Edwards Plateau Savannas is an ecoregion that is intermediate among the dry grassland and savanna ecoregions in terms of rainfall, temperature, and length of growing season. It is estimated that up to 90 percent of this ecoregion has been converted to pasture, urban areas, and agricultural crops. Previously, major disturbance regimes were dominated by fire, drought, and perhaps grazing by bison (Bison bison).
The limestone bedrock of the Edwards Plateau helps to contribute to the distinctiveness of the biota. An array of species are specialists on limestone... More »
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